Research On The Equipment Of Discharge Characteristics Of Nozzles For Gas Extinguishing Systems

Nozzle is one of the most important and widely used components for gas extinguishing systems. The discharge characteristics of nozzle are very important to both the extinguishing result and the security of the extinguishing system. The establishment of the examine equipment for testing the nozzle discharge characteristics is significant to test, inspect, and research the discharge characteristics of nozzles and such type of products.In this paper several kinds of gas extinguishing agent and gas extinguishing systems have been mainly introduced. It also has analyzed the basal theory of the nozzle discharge characteristics and introduced the importance of the discharge characteristics to the design of the gas extinguishing systems. The equipment has been designed and set up according to the basal theory of discharge characteristics. In this paper the design principles of the equipment, the design of the weighing platform and the spray tube, the selection of sensors and data processing have all been specified in detail.Several tests have been done by the equipment to research and analyse the main factors that influence the nozzle discharge characteristics. According to the parallel tests, it has been found that the factors such as charging pressure, agent, nozzle orifice area and etc. will affect the results of discharge characteristics.According to the performance of the test equipment it has been regarded that the design principle is suitable for the equipment effectively and it satisfies the requirement of engineering. Without the complicated flow characteristics analysis and thermodynamic calculation this test method adapted by the equipment is not only suitable for single-phase flow, but also for two-phase flow.The research of the theory and the establishment of the equipment supply the bases for the standard to regulate nozzle discharge characteristics. The national standard drafted in 2006, Perfomance requirements and test methods for components of gas extinguishing systems has regulated discharge characteristic as one of the important performance for nozzles, and it was passed by the standard committee in 2007. So the equipment of flow characteristics provides hardware sustainability for inspecting nozzle discharge characteristics according to the standard.